Along with the continuous development of intelligent services, the number of intelligent users rises continuously. To this end, how to ensure normal calls for intelligent users becomes a matter which may influence the quality of service.
FIG. 1 is a flowchart of originating a call from a prepaid user. As shown in FIG. 1, suppose that the prepaid user is an intelligent user, the specific process of setting up a connection to ensure a call for the prepaid user in the prior art includes the following steps:
Step 101: an originating SSP receives a call from a calling prepaid user, and detects an intelligent trigger named Origination_Attempt_Authorized.
Step 102: the originating SSP sends an ORREQ message to a corresponding SCP according to the address identified in the trigger.
Step 103: upon receiving the ORREQ message, the SCP checks the account balance of the calling prepaid user; if the account balance exceeds a preset limit, proceed to Step 105; otherwise, proceed to Step 104.
Step 104: the SCP returns an orreq message, carrying in the message parameters ACCEDN and ANNLIST to notify the originating SSP that call processing shall be refused, and then terminates the process.
Step 105: the SCP returns an orreq message, carrying in the message a parameter DMH_SVCIDLIST to notify the originating SSP that call processing shall continue.
Step 106: the originating SSP detects an intelligent trigger Calling_Routing_address_Available, and sends an ANLYZD message to a corresponding SCP according to the address identified in the trigger.
Step 107: upon receiving the ANLYZD message, the SCP judges whether the account balance of the user is sufficient to initiate the call; if the account balance is sufficient, proceed to Step 108; otherwise, the SCP notifies the originating SSP to interrupt the call, and terminates the process.
Step 108: the SCP notifies the originating SSP to continue the call, and the originating SSP establishes a connection from the calling user to the called user. Then, the calling user may communicate with the called user after receiving a response from the called user.
It can be seen from the above process that the SCP is a core unit of the entire intelligent network for an intelligent service. When an intelligent call arrives, the SCP will send a series of operating instructions to the SSP, instructing the SSP to perform operations according to the established service logics, and the SSP can not independently implement the whole process of intelligent call by itself.
In practical implementation of intelligent services, however, abnormal situations may occur between the SSP and the SCP. For example, failures such as disconnection or congestion of a link between the SSP and the SCP may occur, which disables message interaction between the SSP and the SCP. For another example, the SCP, which is busy or in failure, can not send operation instructions to the SSP. Thus, when abnormal situations occur between the SSP and the SCP, the SSP can not acquire the operation instruction from the SCP, and therefore can not perform corresponding operation, which makes call proceeding of intelligent users impossible, and hinders normal operations of intelligent services.